Embodiments relate to a semiconductor memory device, and more particularly, to a semiconductor memory device that is favorable to miniaturization, is easy to manufacture, and is partially replaceable.
For electronic devices, small sizes and high capacities have been demanded at the same time. Although the number of semiconductor devices mounted on a substrate having a limited area needs to be increased for high capacities, the area of the substrate needs to be reduced for small sizes. To meet the conflicting needs, a scheme has been proposed in which semiconductor devices to be mounted on one large substrate are mounted on two smaller substrates. To electrically connect the two smaller substrates, connectors are provided corresponding to positions of the substrates, respectively, for interconnection or a flexible printed circuit board is used. However, these methods are not useful because the semiconductor devices are mountable on only facing surfaces or utilization of the area is not efficient.